Switch gear



B. GROB SWITCH GEAR May 31, 1932.

Filed Oct. 15. 1928 Patented May 31, 1932 UNITED STATES PATENr FFICE BENJAMIN GROB, OF WEST ALLIS, WISCONSIN, ASSIGNOR TO ALLIS-CHALMER-S MANU- FACTURING COMPANY, OF MILWAUKEE, VTISCONSIN, A CORPORATION OF DELA- WARE SWITCH GEAR Application filed October 15, 1928. Serial No. 312,421.

This invention relates to electric switches, and more particularly of the non-closable on overload, or trip-free'mechanism type.

One of the objects of the invention is to provide a simple and sturdy construction.

A further object is to provide a trip-free mechanism which is sensitive and may be easily tripped even though the mechanism is utilized in connection with heavy switches involving large forces.

Another object is to provide a switch operating mechanism which will safeguard the switch, and particularly which will prevent slow opening of the switch and consequent destructive arcing. A more specific object is to provide a mechanism which will cause rapid opening'of the switch after closure thereof in case the prime source of power for operating the switch should fail to bring the switch operating mechanism to the fully closed position. Other objects will appear hereinafter as the description of the invention proceeds.

The novel-features of the invention will appear from this specification and the accompanying drawings forming a part thereof and all these novel features are intended to be pointed out in the claims.

' In the drawings:

39 Fig. 1 is a side elevation'of a switch cmbodying the invention, some of the parts being broken away and others shown diagrammatically.

Fig. 2 is a detail of a part of the switch operating mechanism.

Referring to Fig. 1 the switch which is to be operated is shown diagrammatically as having a bridging member 1 which is connected in any suitable manner to an operating means here shown as a lever 2. The bridging member 1 and itsassociated stationary contacts are diagrammatically indicated. The lever 2 is mounted to swing about a shaft or pin 3 which may be suitably mounted in' a housing 20, the rearportion only of which is shown. The lever -2 may consist of two spaced elements and the same is-true of other levers where it is found desirable as a matter ofdesign. 7 v 50 The lever 2 is provided with a pin 4 which is adapted to be engaged by a roller 5. The roller 5 is suitably mounted on a pin 6 carried by a link 7. The link 7 comprises two spaced elements 8, 9 which may be connected by means of a web 10. The element 9 is slightly offset as shown more clearly in Fig. 2 and is provided with a surface 11 which in the position of the parts shown in Fig. 1 is in engagement with the pin 4. The link 7 is pivoted on a pin 12 carried by an actuating lever 13 here shown as of the bell crank type. The actuating lever 13 may swing about a pin or shaft 14 which shaft is suitably mounted in the housing 20.

The actuating lever 13 also carries a pin 15 to which pivotal connection is made by a rod 16 in turn pivoted on the pin .17. The pin 17 is here shown as adaptedto be moved up and down by means of a tubular member 18 connected in any suitable manner to the pin 17 as by the spider 39. Upward movement of the pin 17 may be arrested by means of an abutment 21 carried by the housing 20 in any suitable manner as by means of lugs 40 screwed to the housing. The limiting upper position of the pin 17 may be adjusted by screws 19 which abut against the member 21.

In the position of the parts shown in Fig. 1 the link 7, and consequently the roller 5, is maintained in position by means here shown as a slotted link 22. The slot 41 in said link has an indentation 23 therein which in the position of the parts shown rests on a bushing 25 surrounding the shaft 3. The bushing 25 may, if desired, be omitted. The slotted link 22 carries a roller 24 rotatable about a pin 29. The slotted link is pivotally connected to the part 8 of the link 7 by means of the pin 26. The pin 26 has its axis, in the position of the parts'shown, coincident with the axis of pin 4, so that swinging of the lever 2 about the shaft 3 will not disturb the relation between the roller 24 and the bush ing 25. The roller 24 preferably has its axis slightly below a line joining the center of shaft 3 and the center of pin 4 when the surface 23 rests on the bushing 25.

A trip link 27 is provided for a purpose which will appear hereinafter, this link being pivoted about a in 28 carried by the actuating lever 13. 11 upper side portion of the link 27 is here shown as resting against the pin 29. The link 27 is also provided with a number of shoulders here shown as the shoulders 30, 31. Joining the shoulder 31 is a cam surface 32..

A trip lever 34 is mountedto be rotatable loosely about a shaft 35. The trip lever 34 may be lifted to thereby come into engagement with the slotted link 22, by means of a solenoid 38, which latter may be energized in any desired manner. The trip lever 34 also may carry a pin 36 which is engageable by a pin 37 carried by the shaft 35 so that if desired the shaft 35 may be rotated counterclockwise to lift the trip lever 34 against the slotted link22. The shaft 35 may be mounted in and passed through that portion of the housing which is ordinarily disposed in front of the mechanism as shown in the drawings. It should be noted that the shaft 35 sto s short of the trip link 27.

X bushing 33 shown in dot and dash lines for the sake of clearness, may be disposed about the shaft 3 and serves for one of its purposes to limit any swinging of the slotted link 22 in a direction along the axis of the shaft 3. Another purpose of this bushing will appear hereinafter.

A link 42 loosely pivoted at one end about the pin 4 and loosely pivoted at the other end about the pin 6 is provided for the purpose to be hereinafter noted. It may be statedat this point that the link 42 is looselypivoted as stated so that the pin 4 and consequently the lever 2 will be supported entirely by the roller 5.

The operation. of the illustrated mechanism is as follows. It. may be first noted that the axis of the pin 12 is preferably in such position when the switch 1 is fully closed that it is slightly to the right, as viewed in the drawings, of a line joining the axis of the shaft 14 and the axis of the pin 4. It will be noted that the parts between the axes of pin 4 and of pin 12, and the portion of the actuating lever between the axis of pin 12 and the axis of shaft 14, constitute a toggle which in the position of the parts shown is overset. This toggle tends to collapse by movement of the axis of pin 12 toward the right by reason of thereaction of switch 1 and the action of gravity on the switch parts. It, however, cannot so collapse because the actuating lever cannot rotate clockwise because the upward movement of pin 17 is of the roller is slightly toward the right of normal conditions.

neeasoi the line joining the axis of pin 4 and the axis of pin 12. This position of the roller is determined by the proper position of the surface 11 of the part 9 of link 7. The tendency for rotation of link 7 about pin 12, as hereinbefore noted, is compensated by the slotted link 22 and the roller 24. The slotted link 22 tends to move towards the right but inasmuch as the center of roller 24 is below the line joining the axes of pin 4 and shaft 3, and any clockwise rotation of slotted link 22 about pin 26 is prevented by the surface 23, the slotted link serves to maintain the roller 5 in thrust relation with the pin 4.

In view of the foregoing it will be clear that if the trip lever 34 is moved to cause a slight counter-clockwise rotation of slotted link 22 about the pin 26, the center of roller 24 will be brought above the line 'oining the axis of pin 26 and the axis of shaft 3 and consequently the roller 24 will at first roll upwardly to the right on bushing 25, thereby permitting the lever 2, through pin 4, to force the roller 5 out of the way thus turning the link 7 clockwise. WVhen the mechanism is: thus tripped, it is clear that the switch is free to instantly open irrespective of whether the actuating lever 13 remains in the position shown or not. It is therefore not possible to maintain the switch closed under ab- Ordinarily when the switch is tripped as described the prime operating means 18 will be deenergized, that is, there will be no force tending to hold the member 18 up. Consequently this member will drop carrying with it the link 16 and rotating the actuating lever 13 in the counter clockwise direction. This motion will cause the pin 12 to pull the link 7 downwardly to- Ward the left and with the cooperation of the link 42, the roller 5 will again be brought into thrust relationship with the pin 4 this of course occurring with the lever 2 swung about the shaft 3 in a counter-clockwise direction to a position corresponding to the open position of switch 1. The consequent counter-clockwise rotation of link 7 about pin 12 causes the slotted link 22 to be drawn toward the left and the shaft 3 will again enter the indentation in the slot and the roller 24 will again be in thrust relationship to the bushing '25. The parts are now ready for,

re-closure of switch 1 and when force is ap plied to the member 18 to move it upwardly the actuating lever 13 will by toggle effect bring the switch to closed position as shown in Fig. 1. If inthe meantime the solenoid 38 should be energized to thereby trip the slotted link 22, the switch 1 would of course at once I drop. to the open position irrespective of whether the actuating lever is being controlled by the operating means 18 or not.

' It may be desirable at times to open the switch manually instead of through the trip lever 34. In this case the shaft 14 may be r0- tated in a counter-clockwise direction and the arrangement of the parts is such that before all of the spring pressure of the contacts has been relieved and the switch actually opens, the shoulder 30 will engage the pin 29 (by reason of the counter-clockwise rotation of actuating lever 13) thereby causing tripping of the switch as hereinbefore described in connection with trip lever 34. The opening of the circuit will therefore occur rapidly and will not depend upon the speed of manual rotation of the shaft 14.

In order to prevent damage to the switch if, for example, the operating means 18 should fail to bring the toggle hereinbefore referred to to the overset position, and should move downwardly after such failure, thereby tending to open the switch slowly, the shoulder 31 on the trip link 27 is provided. It will be noted that when the actuating lever 13 is rotated in a counter-clockwise direction the cam surface 32 will engage the bushing 33 thereby slightly swinging the trip link 27 in a counter-clockwise direction. Assuming now that the roller 24 is in thrust relationship with the bushing 25, the shoulder 31 will be in a position adapted to engage the pin 29 if the part 18 should begin to drop back before having fully closed the switch and thus rotate the actuating lever 13 in the counter-clockwise direction. The consequent engagement of shoulder 31 with pin 29 will of course trip the switch. The position of sh oulder 31 is so selected that it will be in a position to engage pin 29 upon any reverse movement of the actuating lever 13 just after said lever has been rotated sufiiciently in a clockwise direction to bring the bridging member 1 in contact with the stationary contacts.

It should be understood that it is not desired to limit the invention to the exact details shown and described, for obvious modifications within the scope of the claims may occur to persons skilled in the art.

It is claimed and desired to secure by Letters Patent:

1. In a switch, operating means for said switch, actuating means for said operating means, a normally positive collapsible mechanism between said actuating and operating means, and means for normally maintaining said collapsible mechanism in its positive condition including a link operatively related to said collapsible mechanism, a stationary abutment, an element carried by said link cooperable with said stationary abutment, and means operative to effect collapse of said collapsible mechanism without affec ing the position of said abutment.

2. In a switch, operating means for said switch, actuating means for said operating means, a normally positive collapsible mechanism between said actuating and operating means, and means for normally maintaining said collapsible mechanism in its positive condition including a link operatively related to said collapsible mechanism, a relatively stationary abutment, a roller carried by said link cooperable with said stationary abutment, and means operable by switchopening movement of said actuating means, for tripping said link.

3. In a switch, operating means for said switch, alever having a relatively stationary pivot, a link pivotally connected to said lever, a normally positive collapsible mechanism between said link and said ope-rating means, said link and its associated collapsible mechanism forming one link of a toggle of which said lever is the other link, said toggle being overset when said switch is closed, and means for normally maintaining said collapsible mechanism in its positive condition including a link operatively related to said collapsible mechanism, a relatively stationary abutment, and a roller carried by said link cooperable with said stationary abutment.

4. In a switch, operating means for said switch, a lever for moving said switch to the closed position, said lever having a relatively stationary pivot, a link pivotally connected to said lever, a roller pivoted on said link, means for normally holding said roller in thrust relationship to said operating means, and means for tripping said holding means.

5. In a switch, operating means for said switch, a lever having a relatively stationary pivot, a linkpivotally connected to said lever, a roller pivoted on said link, means for normally holding said roller in thrust relationship to said operating means, and means operatively related to said lever for tripping said holding means.

6. In a switch, operating means for said switch, a lever having a relatively stationary pivot, a link pivotally connected to said lever, a roller pivoted on said link, means for normally holding said roller in thrust relationship to said operating means, means for tripping said holding means, and means including an auxiliary link connecting said operating means and said first named link for returning said roller into thrust relationship to said operating means.

7. In a switch, operating means for said switch, actuating means for said operating means, means for transmitting motion from said actuating means to said operating means including an operating toggle between. said two means, said toggle including as one element thereof a lever having a stationary pivot and as the other element a link pivoted to said lever, along with a roller pivoted on said link cooperable with said operating means, means for normally holding said roller in thrust relationship to said operating means, said toggle being overset when said switch is closed, and means for stopping said toggle in the overset position.

8. In a switch, operating means for said switch, actuating means for said operating means, a normally positive collapsible mech anism between said operating and actuating means, means for normally maintaining said mechanism in its positive condition, and means operatively related to said actuating means for tripping said maintaining means upon reversal of the movement of said actw ating means toward closed position before said actuating means has reached its fully closed position.

9. In a switch, an operating lever having a stationary pivot, actuating means for said operating lever, a normally positive collapsible mechanism between said actuating means and said operating lever, and means for maintaining said collapsible mechanism in its positive condition including a slotted link pivoted thereto, said stationary pivot being disposed in said slot, and a roller pivoted to said link cooperable in thrust relationship with said stationary pivot.

10. In a switch, an operating lever having a stationary pivot and carrying a pin, an actuating lever having a stationary pivot, a link pivoted to said actuating lever, a roller pivoted to said link cooperable in thrust relationship with said pin, a slotted link pivoted to the aforesaid link on an axis coincident with the axis of said pin when said roller is in thrust relationship with said pin, said stationary pivot being disposed in said slot, and a roller carried by said slotted link cooperable in thrust relationship with said stationary pivot.

11. In a switch, an operating lever having a stationary pivot and carrying a pin, an actuating lever having a stationary pivot, a link pivoted to said actuating lever, a roller pivoted to said link cooperable in thrust relationship with said pin, a slotted link pivoted to the aforesaid link on an axis coincident with the axis of said pin when said roller is in thrust relationship with said pin, said stationary pivot being disposed in said slot, a roller carried by said slotted link cooperable in thrust relationship with said stationary pivot, and a trip-link pivoted to said actuating lever, said trip-link having a shoulder cooperable with said slotted link whereby a movement of said actuating lever in the switch-opening direction will bring said roller carried by said slotted link out of thrust relationship with said stationary pivot.

12. In a switch, an operating lever having a stationary pivot and carrying a pin, an actuating lever having a stationary pivot, a link pivoted to said actuating lever, a. roller pivoted to said link cooperable in thrust relationship with said pin, a slotted link pivoted to the aforesaid link on an axis coincident with the axis of said pin when said roller is in thrust relationship with said pin, said stationary pivot being disposed in said slot, a roller carried by said slotted link cooperable in thrust relationship with said stationary pivot, and a trip-link pivoted to said actuating lever, said trip-link having a predetermined number of shoulders cooperable with said slotted link whereby a movement of said actuating lever in switch-opening direction from a predetermined number of positions of said actuating. means will bring said roller carried by said slotted link out of thrust relationship with said stationary pivot.

In testimony whereof, the signature of the inventor is afiixed hereto. BENJAMIN GROB. 

